Medeiros, José Renan deOliveira, Luciano Luiz Alencar de2020-10-142020-10-142019-12-16OLIVEIRA, Luciano Luiz Alencar de. A rotação estelar revelada pela modulação fotométrica. 2019. 105f. Tese (Doutorado em Física) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2019.https://repositorio.ufrn.br/handle/123456789/30423Stellar rotation is one of the most important parameters in astrophysics and its effects are observed in all evolutionary stage, since the beginning. This present work shows an analysis of the rotation from photometric measures along the Hertzsprung-Russell diagram (HR diagram), for stars in different evolutionary stages, such as: main sequence, subgiants, giants, bright giants and supergiants Ib. We use stellar evolution models with rotation, in which the metallicity are z = 0, 002 and z = 0, 014, presented respectively by Georgy et al. (2013b) and Ekström et al. (2012). Through the measurement of angular rotation velocities, Ω, presented in the models, we estimate the rotation period for each evolutionary track (with masses ranging from 0, 8M < M ≤ 20M ) and consequently we determine the rotation isoperiodic lines using the interpolation technique cubic spline for a effective temperature region 3.500 < Tef ≤ 10.500 K and luminosity −1, 0 < Log (L/L ) ≤ 5, 5. The interpolation technique was utilized to the mean values ±5% of the desired measurements, which are 5, 15, 25, 50 and 100 days. Combining isoperiods to the distribution of rotation period values of our samples, we have observed a significant congruence between the theoretical data and the observed data, for stars with rotation period determined by photometric modulation, as well as periods estimated from v sen i. However, some stars may present a rotational behavior that diverges from the rotation isoperiods. Furthermore, our results show that the discontinuity in the rotation period happens gradually and in every luminosity class, in both the vertical direction (which depends on the stellar luminosity and mass) and the horizontal direction (which depends on the effective temperature) in the HR diagram. The discontinuity in the rotation period is more evident in stars which the periods were estimated from the projected rotation velocity. Such effect happens more clearly between masses 0, 8M < M ≤ 1, 35M , around 5.500 K, for stars with [F e/H] = −1, 0 ± 0, 5 dex. On the other side, stars with [F e/H] = 0, 0 ± 0, 5 dex that present discontinuity in the rotation period have masses between 0, 9M < M ≤ 2M in the Tef ≤ 6.200 K region.Acesso AbertoModelos estelaresPeríodo de rotaçãoVelocidade de rotação projetadaDescontinuidadeDiagrama Hertzsprung-RusselldoctoralThesis